Remote indicator module

ABSTRACT

A vehicle occupant restraint system having a base system and a supplemental system is provided. The base system includes an air bag module and an occupant restraint controller. In the absence of the supplemental system, the occupant restraint controller operates in a default mode wherein the air bag module is enabled. Coupling the supplemental system to the base system permits the air bag module to be selectively disabled. The supplemental system transmits a plurality of signals to indicate whether the air bag module is to be disabled or enabled. When the occupant restraint controller receives a signal indicating that the air bag module is to be disabled, the occupant restraint controller inhibits the generation of squib pulses which would cause the air bag module to actuate.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. application Ser. No. 09/321,000, filed May 27, 1999.

BACKGROUND OF THE INVENTION

[0002] 1. Technical Field

[0003] The present invention relates generally to airbag module control systems and more particularly to a remotely indicating electronic controller with full diagnostics for an airbag module able/disable control system.

[0004] 2. Discussion

[0005] Modern vehicles are typically equipped with one or more airbags which are controlled by an electronic controller. The electronic controller analyzes data received from a variety of sensors located throughout the vehicle and determines whether to inflate the airbag, and in some systems, affects the rate at which the airbag should be inflated. Despite the significant benefits derived generally from the use of such airbag modules, there are circumstances under which an airbag should not be deployed.

[0006] Several control systems have been developed to automatically determine when such circumstances exist. These control systems typically rely on a plurality of sensors to detect or quantify a plethora of variables which are employed in an attempt to quantify the relationship between a seating area and the person or object placed in the seating area. Such systems have not been received with commercial acceptance due to their cost, inability to completely identify all situations in which an air bag module should not be deployed and/or the extreme difficulty incurred to incorporate them into a vehicle after it has been manufactured. Consequently, many consumers simply prefer a system which permits one or more air bag modules to be selectively disabled.

[0007] The disabling systems known in the art have relied on a switch which mechanically breaks or interrupts the squib circuit used to initiate the inflation of an air bag. Despite the apparent success of such systems, several drawbacks are apparent.

[0008] Several of these drawbacks relate to the mechanical interruption of the electronic squib circuit and the effect this has on the integrity and reliability of the air bag module. Such drawbacks include the potential for error when installing the switch, the inability to detect failed or burned out indicators and the inability of the air bag controller to perform diagnostics on all new circuits.

[0009] Another significant drawback relates to the use of such system with sophisticated, multi-stage air bag modules. Modern, sophisticated air bag modules utilize inflators which typically employ two or more squib circuits, each of which are deployable independently of the others. Deployment of the squib circuits is controlled according to a deployment methodology which generally tailors the deployment rate (i.e., inflation rate) to the magnitude of the collision.

[0010] Consequently, where multiple squib circuits are utilized, mechanical disablement of the squib circuits would require several switches. In such a system, effectively disabling an air bag module would require that all of the switches be set to mechanically interrupt their respective squib circuits; a failure to set a single switch correctly would prevent the air bag module from functioning as had been intended.

[0011] Accordingly, there remains a need in the art for a vehicle occupant restraint system which permits air bag modules having two or more squib circuits to be disabled in a convenient and reliable manner. There remains a need in the art for a vehicle occupant restraint system which can be easily and reliably upgraded with controls permitting the vehicle occupants to selectively disable one or more air bag modules. There also remains a need in the art for a vehicle occupant restraint system which can fully diagnose any probable failures in the system and provide for basic backup in the event of a failure.

SUMMARY OF THE INVENTION

[0012] It is therefore one object of the present invention to provide a vehicle occupant restraint system which may be easily and reliably upgraded to permit one or more of the system air bag modules to be disabled.

[0013] It is another object of the present invention to provide a vehicle occupant restraint system which permits one or more of the system air bag modules to be disabled without effecting the system diagnostic capabilities.

[0014] It is a further object of the present invention to provide a vehicle occupant restraint system which permits the system air bags to be disabled in a manner which does not mechanically interrupt the system squib circuits.

[0015] The vehicle occupant restraint system of the present invention includes a base system and a supplemental system. The base system includes an air bag module and an occupant restraint controller. In the absence of the supplemental system, the occupant restraint controller operates in a default mode wherein the air bag module is always enabled. Coupling the supplemental system to the base system permits a plurality of air bag modules to be selectively disabled. The supplemental system transmits a plurality of signals to indicate whether the air bag module is to be disabled or enabled. When the occupant restraint controller receives a signal indicating that the air bag module is to be disabled, the occupant restraint controller inhibits the generation of squib pulses which would cause the air bag module to deploy.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, wherein:

[0017]FIG. 1 is a schematic diagram of a vehicle occupant restraint system constructed in accordance with the teachings of the present invention;

[0018]FIG. 2 is an enlarged view of a portion of the schematic diagram shown in FIG. 1; and

[0019]FIG. 3 is a schematic illustration in flowchart form of the diagnostic capabilities of the remote indicator module.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] Referring to FIGS. 1 and 2 of the drawings, the vehicle occupant restraint system of the present invention is generally indicated by reference numeral 10.

[0021] Those skilled in the art will readily understand that the vehicle occupant restraint system 10 is intended to be integrated into a vehicle 12, which is only shown schematically in FIG. 2, and as such, a detailed discussion of the remainder of the vehicle 12 is neither within the scope of this disclosure nor necessary for practicing the present invention. The vehicle occupant restraint system 10 includes a base system 14 and a supplementary system 18 operable for selectively enabling or disabling all or part of the base system 14. The base system 14 includes an occupant restraint controller 22 and a plurality of multi-stage air bag modules 26. The supplementary system 18 includes a switch unit 30, and a remote indicator module 34.

[0022] The occupant restraint controller 22 includes a microprocessor 38, memory 42, a timer 46 and a communications bus interface device 48. The occupant restraint controller 22 is operable for monitoring the electrical integrity of the base system 14 through periodic diagnostic monitoring, as well as for initiating and controlling the deployment of the plurality of air bag modules 26 a and 26 b. The occupant restraint controller 22 is coupled to various vehicle sensors such as impact sensor 50, which permit the occupant restraint controller 22 to monitor various vehicle dynamics in order to determine the occurrence and severity of a collision.

[0023] As each of the multi-stage air bag modules 26 a and 26 b is similarly constructed, only air bag module 26 a will be discussed in detail. Those skilled in the art will understand, however, that air bag module 26 b includes similar or corresponding elements to the elements of air bag module 26 a. Accordingly, the similar or corresponding elements of air bag module 26 b are identified by the same reference numerals as used to describe the elements of air bag module 26 a, except that the reference numerals for the air bag module 26 b include a “b” suffix.

[0024] Air bag module 26 a includes an inflator 58 a, first and second squib circuits 62 a and 64 a, respectively, and an air bag 68 a. It will be understood, however, that the present invention has applicability to air bag modules of various other configurations and as such, the scope of the present invention is not limited to air bag modules having two squib circuits. The first squib circuit 62 a includes a negative circuit element 72 a, a positive circuit element 74 a and a first squib 76 a which is coupled to the inflator 58 a proximate a first charge 78 a. The negative and positive circuit elements 72 a and 74 a electrically couple the first squib 76 a to the occupant restraint controller 22. The second squib circuit 64 a includes a negative circuit element 82 a, a positive circuit element 84 a and a second squib 86 a which is coupled to the inflator 58 a proximate a second charge 88 a. The negative and positive circuit elements 82 a and 84 a electrically couple second squib 86 a to the occupant restraint controller 22.

[0025] When it becomes necessary to deploy an air bag, such as the air bag 68 a for example, the occupant restraint controller 22 generates a series of squib pulses according to a predetermined deployment method. A detailed description of deployment methodology is beyond the scope of the present invention and need not be provided herein. Briefly, the squib pulses are selectively generated to deploy the air bag 68 a at a predetermined deployment rate consistent with the various dynamics, including the magnitude and duration of the impact.

[0026] Generation of a first squib pulse causes the first squib 76 a to heat and ignite the first charge 78 a. Combustion of the first charge 78 a produces a first volume of gas which is directed into the air bag 68 a causing it to inflate at a first rate. Generation of a second squib pulse causes the second squib 86 a to heat and ignite the second charge 88 a. Combustion of the second charge 88 a produces a second volume of gas which is directed into the air bag 68 a causing it to inflate at a second rate. As one skilled in the art may appreciate, the generation of the first and second squib pulses may be controlled by the occupant restraint controller 22 so as to optimize for a given collision the timing of the airbag inflation, as well as the rate at which the air bag 68 a is inflated. As one skilled in the art may also appreciate, the first and second charges 78 a and 88 a may be sized differently (i.e., non-equally) to further optimize the performance of the air bag module 26 a.

[0027] In the absence of the supplementary system 18, occupant restraint controller 22 operates in a default mode wherein each of the plurality of air bag modules 26 a and 26 b are enabled for deployment. The incorporation of the supplementary system 18 into the vehicle occupant restraint system 10 permits a vehicle operator to selectively disable one or more of the plurality of air bag modules 26 a and 26 b.

[0028] The switch unit 30 of the supplementary system 18 is positionable at a plurality of predetermined switch positions 100 which permit the vehicle occupants to selectively enable or disable one or more of the plurality of air bag modules 26 a and 26 b. The switch unit 30 preferably includes an identification resistor 102 which permits the switch unit 30 to produce a switch-type signal. The magnitude of the resistance of identification resistor 102 is varied according to the type of switch utilized and/or the specific air bag modules 26 a and 26 b that are permitted to be selectively disabled. As illustrated, for example, the switch unit 30 includes an identification resistor 102 having a first resistance value of approximately 88.7 ohms which causes the switch-type signal to achieve a first voltage. Where a different switch unit 30 is used, such as a two-position switch used to selectively disable only the driver side air bag module (i.e., air bag module 26 a), an identification resistor 102 of a second resistance value, 357 ohms for example, is incorporated into the switch unit 30 and causes the switch-type signal to achieve a second voltage. Where another switch 30 is used, such as a two-position switch to selectively disable only the passenger side air bag module (i.e., air bag module 26 b), an identification resistor 102 of a third resistance value, 178 ohms for example, is incorporated into the switch unit 30 and causes the switch-type signal to achieve a third voltage.

[0029] The switch unit 30 preferably produces a predetermined discrete output signal indicative of its placement at a given switch position 100. In the example illustrated, switch unit 30 is operable in four switch positions 100 a, 100 b, 100 c and 100 d which produce a discrete output signal to wires 104 a, 104 b, 104 c and 104 d, respectively. Alternatively, switch unit 30 could comprise a resistive multiplexed switch (not shown) which produces a single output signal that is varied according to the switch position 100.

[0030] The remote indicator module 34 is a microprocessor controlled, data storing indicator assembly which is preferably mounted on top of the instrument panel of a vehicle. The remote indicator module 34 includes a water-resistant housing 120, a pair of indicator lamps 124 a and 124 b (each of which is preferably a light-emitting diode 126), a pair of lamp drivers 128 a and 128 b operable for selectively powering lamps 124 a and 124 b, respectively, and a microprocessor 132 having memory 136, a flash EEPROM 138 and a communications bus interface device 134. The memory 136 permits the microprocessor to log faults and store data and the flash EEPROM 138 permits the microprocessor to be programmed or re-programmed with special instructions which cover all vehicles or base systems 14, within a defined range. These special instructions preferably include the air bag modules which may be selectively disabled (e.g., driver's air bag module 26 a only, passenger's air bag module 26 b only, both air bag modules 26 a and 26 b). Consequently, the remote indicator module 34 may be readily employed in a wide range of vehicles.

[0031] The remote indicator module 34 is coupled to switch unit 30 through the wires 104 a, 104 b, 104 c, 104 d and 104 e. The wires 104 a, 104 b, 104 c and 104 d transmit the discrete output signal produced by switch positions 100 a, 100 b, 100 c and 100 d, respectively, to the remote indicator module 34. The wire 104 e transmits the switch-type signal from the switch unit 30 to the remote indicator module 34. The switch-type signal permits the remote indicator module 34 to identify the air bag module or modules 26 a and 26 b which may be selectively disabled. The remote indicator module 34 evaluates the discrete output signal from the switch unit 30 and determines if the switch position 100 identified by the remote indicator module 34 is a valid position. The switch-type signal therefore prevents the disabling of an air bag module 26 a and 26 b where the switch unit 30 has not been coupled to the remote indicator module 34 in a correct manner or where an unauthorized or incorrect switch unit is employed.

[0032] The remote indicator module 34 by it's communications bus interface device 134 is coupled to the occupant restraint controller 22 through a data link 140 which permits the switch position 100 to be communicated to the occupant restraint controller 22. Preferably, the data link 140 is a serial data link 142, such as an S.A.E. J1850 data bus, which facilitates two-way common communication between the occupant restraint controller 22 and the remote indicator module 34. This permits, for example, the occupant restraint controller 22 to send the remote indicator module 34 a message or signal to dim lamps 124 a and 124 b where the vehicle operator has switched on the vehicle headlights. The remote indicator module 34 is also coupled to the vehicle electric source, such as a battery 146, and the vehicle ground 150.

[0033] The remote indicator module 34 is operable for monitoring the discrete output signals generated by the switch unit 30, and sending messages or signals to the occupant restraint controller 22. For example, when the remote indicator module 34 sends the occupant restraint controller 22 a message to indicate that one of the air bag modules 26 a and 26 b is to be disabled, the occupant restraint controller 22 verifies that the content of the message is within a predetermined set of criteria (e.g., the message is in the proper format, communication with the remote indicator module 34 is correct as verified by a checksum) and thereafter issues the remote indicator module 34 an appropriate response, such as an acknowledgement that a selected one or more of the air bag modules 26 a and 26 b is disabled. In response to this reply from the occupant restraint controller 22, the remote indicator module 34 controls the illumination of the lamps 124 a and 124 b in a predetermined manner. Thereafter, the occupant restraint controller 22 electronically controls the generation of squib pulses to the plurality of air bag modules 26 a and 26 b in a predetermined manner consistent with the position of the switch unit 30. More specifically, the disablement of a particular air bag module 26 a or 26 b is effected through software which inhibits the occupant restraint controller 22 from generating any squib pulses which would cause any of the charges in the particular air bag module 26 a or 26 b to ignite.

[0034] Advantageously, the remote indicator module 34 enables the air bag modules 26 a and 26 b to be selectively disabled without mechanically interrupting their respective squib circuits. This strategy maintains the integrity of the base system 14 and permits the occupant restraint controller 22 to continuously monitor the switch position of the switch unit 30. Consequently, the remote indicator module 34 provides the vehicle occupant restraint system 10 with enhanced reliability.

[0035] The remote indicator module 34 is also operable for performing diagnostic testing in connection with the vehicle occupant restraint system 10 to identify faults within the supplementary system 18, the occupant restraint controller 22 and in the communications between the supplementary system 18 and the occupant restraint controller 22. With reference to FIG. 3, the diagnostic testing begins at bubble 198 and proceeds to block 200 where the remote indicator module 34 is initialized upon the turning of an ignition key (not shown) and ignition cycle counters in both the remote indicator module 34 and the occupant restraint controller 22 are incremented. The methodology then proceeds to decision block 202 where the methodology determines whether a fault has occurred within the remote indicator module 34 during the initialization process. If a fault has occurred within the remote indicator module 34 during the initialization process, the methodology proceeds to block 206 where the fault is logged into a fault log and the fault is communicated over the data link 140 to the occupant restraint controller 22 and various other control devices (not specifically shown). Thereafter, the methodology proceeds to block 210 which will be discussed in further detail, below.

[0036] If a fault has not occurred within the remote indicator module 34 during the initialization process, the methodology proceeds to block 204 where the methodology determines whether a fault has occurred between the switch unit 30 and the remote indicator module 34. These faults include, for example, a short-to-ground condition with one of the wires 104 a, 104 b, 104 c and 104 d, a short of one of the wires 104 a, 104 b, 104 c and 104 d to another one of the wires 104 a, 104 b, 104 c and 104 d and an open circuit condition within the entire switch unit 30. If a fault is detected between the switch unit 30 and the remote indicator module 34 in decision block 204, the methodology proceeds to block 208 where the remote indicator module 34 records the fault in a fault log in the memory 136 of the microprocessor 132, increments a fault counter that is specific to the type of fault detected (e.g., a short in the wire 104 b) and communicates the fault over the data link 140 to the occupant restraint controller 22 and various other control devices (not specifically shown). Thereafter, the methodology proceeds to block 210.

[0037] In block 210, the occupant restraint controller 22 determines the last known “good” switch position (i.e., the valid switch position immediately identified prior to the communication of a fault from the remote indicator module 34), records the fault in a fault log in the memory of its microprocessor, increments a fault counter that is specific to the type of fault detected and requests that the vehicle restraint system fault indicator 154 be illuminated to indicate that servicing of the occupant restraint system 10 is required. The methodology then proceeds to decision block 220.

[0038] Returning to decision block 204, if a fault is not detected between the switch unit 30 and the remote indicator module 34 in decision block 204, the methodology proceeds to decision block 207 where the methodology determines whether a fault has occurred in the data link 140. These faults include situations where valid communication cannot be established between the remote indicator module 34 and the occupant restraint controller 22, as when a checksum figure that does not match the actual checksum of the message is provided.

[0039] If a fault is detected in the data link 140 in decision block 207, the methodology proceeds to block 208. If a fault is not detected in the data link 140 in decision block 207, the methodology proceeds to decision block 216. In decision block 216, the methodology determines whether a fault has occurred within the remote indicator module 34 hardware. These faults include, for example, failures or faults in the remote indicator module's RAM, ROM, micro-processor or analog-to-digital converter, as well as faults within the lamps 124 a and 124 b and their associated lamp drivers (e.g., short-to-battery and open conditions). If a fault has occurred in the remote indicator module 34 hardware in decision block 216, the methodology proceeds to block 208. If a fault has not occurred in the remote indicator module 34 hardware in decision block 216, the methodology proceeds to decision block 220.

[0040] In decision block 220 , the methodology determines whether normal operations of the occupant restraint system 10 have been established. The methodology reviews the faults that have been registered in each of the fault counters and determines whether the exact same fault (e.g., a short in wire 104 b) has not been registered in each of the last five diagnostic cycles (i.e., loops through the methodology through decision block 216 or block 210 to decision block 220).

[0041] If any fault has been registered in any of the last five diagnostic cycles, normal operations have not been established and immediate servicing of the occupant restraint system 10 is required. The vehicle restraint system fault indicator 154 is maintained in an illuminated state to indicate that servicing of the occupant restraint system 10 is required. Those skilled in the art will understand that the use of five diagnostic cycles is merely exemplary and that the actual number of cycles may be varied as desired. The methodology then loops back to decision block 204.

[0042] If no faults have been registered in any of the last five diagnostic cycles in decision block 220, normal operation of the occupant restraint system 10 have been established and the methodology proceeds to block 224. In block 224, the occupant restraint controller 22 generates a command to turn the vehicle restraint system fault indicator 154 off and communications between the occupant restraint controller 22. The methodology then proceeds to decision block 228.

[0043] In decision block 228, the methodology evaluates each of the fault counters and the ignition cycle counters and determines for each of the fault counters whether a predetermined number of ignition cycles (e.g., 100 ignition cycles) have occurred without the triggering of an associated fault. If a predetermined number of ignition cycles has not elapsed without the triggering of a fault, the counter that is associated with the fault is not reset and the methodology loops back to decision block 204. If, however, at least one of the fault counters has not registered an associated fault throughout the predetermined number of ignition cycles, the methodology proceeds to block 232. In block 232, those fault counters that have not registered an associated fault after the predetermined number of ignition cycles has elapsed are reset. The methodology then loops back to decision block 204.

[0044] The use of a single vehicle restraint system fault indicator 154 to alert vehicle occupants to the presence of a fault within either the base system 14 or the supplementary system 18 avoids confusion on the part of the vehicle occupants. Technicians who subsequently trouble-shoot the vehicle occupant restraint system 10 may utilize the memory and data storage capabilities of the occupant restraint controller 22 and remote indicator module 34 to identify whether the fault occurred in the base system 14 or the supplementary system 18.

[0045] From the forgoing, those skilled in the art should readily understand that the supplementary system 18 may be overlayed onto the base system 14 in a simple and reliable manner. Installation of the supplementary system 18 requires the mounting of the remote indicator module 34 and the switch unit 30, the connection of a first wire 158 to the vehicle power source (e.g., battery 146), the connection of a second wire 162 to the vehicle ground 150 and the connection of a third wire 142 to the vehicle data link 140 which couples the remote indicator module 34 to the vehicle data link system (not specifically shown) to permit the remote indicator module 34 to communicate over the data link 140 with the occupant restraint controller 22.

[0046] While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the description of the appended claims. 

What is claimed is:
 1. An occupant restraint system for a vehicle, said occupant restraint system comprising: an air bag module having an air bag and a first squib circuit; an occupant restraint controller coupled to said first squib circuit and operable for generating a first squib pulse to cause said first squib circuit to deploy said air bag; a remote indicator module coupled to said occupant restraint controller via a common communications data bus; and a switch coupled to said remote indicator module, said switch movable between a first switch position and a second switch position, said switch producing a first switch position signal when placed in said first switch position and said switch producing a second switch position signal when placed in said second switch position; said remote indicator module receiving said first switch position signal and transmitting a first signal over said common communications data bus in response thereto, said occupant restraint controller receiving said first signal and not inhibiting said first squib pulse from being generated to thereby permit the air bag module to be selectively deployed; said remote indicator module receiving said second switch position signal and transmitting a second signal over said common communications data bus in response thereto, said occupant restraint controller receiving said second signal and inhibiting said first squib pulse from being generated to thereby disable said air bag module.
 2. The occupant restraint system of claim 1, wherein said first switch position signal is a first discrete output signal transmitted to said remote indicator module through a first wire and said second switch position signal is a second discrete output signal transmitted to said remote indicator module through a second wire.
 3. The occupant restraint system of claim 1, wherein said switch is a resistively characterized switch.
 4. The occupant restraint system of claim 1, wherein said remote indicator module includes a lamp and a lamp driver for selectively operating said lamp when said switch is placed in one of the first and second switch positions.
 5. The occupant restraint system of claim 1, wherein said lamp is operated in response to a response sent from the occupant restraint controller and received by the remote indicator module indicating that the occupant restraint controller has disabled the air bag module.
 6. The occupant restraint system of claim 1, wherein said remote indicator module and said occupant restraint controller are coupled by a serial data link.
 7. The occupant and supplemental restraint system of claim 6, wherein said serial link is an S.A.E. J1850 data bus.
 8. The occupant restraint system of claim 1, wherein said occupant restraint controller is operable for performing a diagnostic test on said air bag module wherein said diagnostic test is not effected when said air bag module is disabled.
 9. The occupant restraint system of claim 1, wherein said remote indicator module includes a set of diagnostic test capabilities which are contained as a set of instructions stored in said memory.
 10. The occupant restraint system of claim 9, wherein the set of diagnostic test capabilities tests for faults within the remote indicator module.
 11. The occupant restraint system of claim 10, wherein the remote indicator module includes a lamp that is operable in an illuminated condition when said switch is placed in the second switch position and the faults within the remote indicator module include an open condition in the lamp and a short-to-battery condition in the lamp.
 12. The occupant restraint system of claim 9, wherein the set of diagnostic test capabilities tests for faults between the switch and the remote indicator module.
 13. The occupant restraint system of claim 12, wherein the faults between the switch and the remote indicator module include a short-to-ground condition of a first electrical conductor, a short from the first electrical conductor to a second electrical conductor and an open condition within the entire switch.
 14. The occupant restraint system of claim 9, wherein the set of diagnostic test capabilities tests for faults with the occupant restraint controller.
 15. The occupant restraint system of claim 14, wherein the faults with the occupant restraint controller include a failure of the occupant restraint controller to generate a reply to a message sent by the remote indicator module, or a reply sent by the occupant restraint controller that is valid but inconsistent with the message sent by the remote indicator module.
 16. The occupant restraint system of claim 9, further comprising a vehicle restraint system fault indicator, the vehicle restraint system fault indicator being normally maintained in an illuminated condition for signaling a fault in the occupant restraint system, the vehicle restraint system fault indicator being responsive to the set of diagnostic capabilities such that the vehicle restraint system fault indicator is maintained in an unilluminated condition only if the set of diagnostic test capabilities performs a predetermined number of diagnostic iterations and fails to detect a fault.
 17. In a vehicle occupant restraint system having an air bag module and an occupant restraint controller operable for deploying said air bag module, a supplemental system for selectively inhibiting deployment of said air bag, said supplemental system comprising: a remote indicator module; and a switch coupled to said remote indicator module, said switch movable between a first switch position and a second switch position, said switch producing a first switch position signal when placed in said first switch position and said switch producing a second switch position signal when placed in said second switch position; said remote indicator module receiving said first switch position signal and transmitting a first signal in response thereto, said first signal configured for electronically permitting said occupant restraint controller to deploy said air bag module; said remote indicator module receiving said first switch position signal and transmitting a first signal in response thereto, said first signal configured for electronically inhibiting said occupant restraint controller from deploying said air bag module.
 18. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said first switch position signal is a first discrete output signal transmitted to said remote indicator module through a first wire and said second switch position signal is a second discrete output signal transmitted to said remote indicator module through a second wire.
 19. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said switch is a multi-contact switch.
 20. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said remote indicator module includes a lamp and a lamp driver for selectively operating said lamp when said switch is placed in one of the first and second switch positions.
 21. The supplemental system for selectively inhibiting deployment of an air bag of claim 20, wherein said remote indicator module and said occupant restraint controller are coupled by a serial data link.
 22. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said remote indicator module and said occupant restraint controller are coupled by a serial data link.
 23. The supplemental system for selectively inhibiting deployment of an air bag of claim 22, wherein said serial link is an S.A.E. J1850 data bus.
 24. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said occupant restraint controller is operable for performing a diagnostic test on said air bag module wherein said diagnostic test is not effected when said air bag module is disabled.
 25. The supplemental system for selectively inhibiting deployment of an air bag of claim 24, wherein said remote indicator module includes a set of diagnostic test capabilities.
 26. The supplemental system for selectively inhibiting deployment of an air bag of claim 25, wherein the set of diagnostic test capabilities tests for faults within the remote indicator module.
 27. The supplemental system for selectively inhibiting deployment of an air bag of claim 26, wherein the remote indicator module includes a lamp that is operable in an illuminated condition when said switch is placed in the second switch position and the faults within the remote indicator module include an open condition in the lamp and a short-to-battery condition in the lamp.
 28. The supplemental system for selectively inhibiting deployment of an air bag of claim 25, wherein the set of diagnostic test capabilities tests for faults between the switch and the remote indicator module.
 29. The supplemental system for selectively inhibiting deployment of an air bag of claim 28, wherein the faults between the switch and the remote indicator module include a short-to-ground condition of a first electrical conductor, a short from the first electrical conductor to a second electrical conductor and an open condition within the entire switch.
 30. The supplemental system for selectively inhibiting deployment of an air bag of claim 25, wherein the set of diagnostic test capabilities tests for faults with the occupant restraint controller.
 31. The supplemental system for selectively inhibiting deployment of an air bag of claim 30, wherein the faults with the occupant restraint controller include a failure of the occupant restraint controller to generate a reply to a message sent by the remote indicator module, or a reply sent by the occupant restraint controller that is valid but inconsistent with the message sent by the remote indicator module.
 32. The supplemental system for selectively inhibiting deployment of an air bag of claim 25, further comprising a system fault light, the system fault light being normally maintained in an illuminated condition for signaling a fault in the occupant restraint system, the remote indicator module being operable for generating a signal to turn the fault light off if the set of diagnostic test capabilities fails to identify a fault.
 33. The supplemental system for selectively inhibiting deployment of an air bag of claim 17, wherein said switch produces a switch-type signal indicative of the location of said air bag module which may be selectively disabled. 